minor updates (#208)

* update vignette + workflow pkgdown

Author: berthetclement

Diff for: .github/workflows/pkgdown.yaml

@@ -6,7 +6,7 @@ on:
   push:
     branches: [release/9.2]
   pull_request: 
-    branches: [master, release/9.2]
+    branches: [master]
 
   release:
     types: [published]

Diff for: vignettes/Antares_new_features_v920.Rmd

@@ -20,9 +20,11 @@ library(antaresEditObject)
 
 This article will present the new features in line with **Antares v9.2** (cf  [Antares Simulator](https://antares-simulator.readthedocs.io/en/latest/user-guide/04-migration-guides/#v920))
 
-**New features** :  
+## New features
 
-> For 'st-storages', Parameter `group` is now dynamic and have no restriction for user  
+**Short Term Storages**  :
+
+  - Parameter `group` is now dynamic and have no restriction for user  
 
 
 ## Create new study v9.2